Endometrial cancer (EC) is a prevalent gynecological cancer with an escalating global incidence and a decreasing age of onset. In the era of precision medicine, there is an increasing emphasis on tailoring treatments to different populations to optimize the positive impact of clinical interventions. Fertility-sparing therapies (FST) are gaining popularity for early-stage, low-grade endometrial cancer due to mounting evidence supporting favorable oncologic and pregnancy outcomes. However, consensus regarding the feasibility of fertility-sparing therapy for similar low-risk grade-2 (G2) endometrioid adenocarcinoma remains elusive. Given the uncertainties surrounding fertility-preserving therapy in patients with moderately differentiated endometrial cancer, this study aims to investigate the optimal regimen of fertility-preserving therapy for patients with IAG2.

This study aims to explore effective treatment options and pregnancy outcomes for G2 EC patients who wish to preserve their fertility. It compares the efficacy of monotherapy with progesterone versus combined therapy to determine the best treatment option.

This study is a multi-center, prospective, randomized controlled trial that collects hospital and outpatient records of uterine endometrioid adenocarcinoma patients who undergo fertility-sparing treatment at 10 units from October 2022. The basic items specified in the study are registered.

Selection criteria: Pathological diagnosis of endometrioid adenocarcinoma G2, MRI or ultrasound confirmed localization of the lesion within the endometrium, FIGO (FIGO, 2009) staging IA, age ≤ 45 years, and those who wish to preserve reproductive function, signed informed consent. Exclusion criteria: Tumor invasion of the muscle layer, FIGO (FIGO, 2009) staging IB or higher, tumor differentiation as G1, G3, or non-endometrioid adenocarcinoma, coexistence of malignant tumors in other sites, contraindications or drug prohibitions for conservative treatment, or judged by the investigator to be unsuitable for childbearing. Exclusion criteria: Violation of the treatment protocol; failure to take medication as prescribed, affecting the judgment of drug efficacy; incomplete data affecting the judgment of efficacy and safety. Withdrawal criteria: Intolerance of the used drugs or the appearance of serious complications, including venous or arterial thromboembolism, liver failure, renal failure, anaphylaxis, uterine perforation, etc.; no response to treatment or disease progression during drug therapy; when the patient requests termination of treatment.

Treatment Plan: The treatment plan was randomly divided into two groups. Group 1 was a single-drug treatment plan, with oral medroxyprogesterone acetate (MPA) 500mg/d or megestrol acetate (MA) 320mg/d; Group 2 was a combined treatment plan, with oral MPA 500mg/d/MA 320mg/d combined with the placement of levonorgestrel intrauterine system (LNG-IUS) in the uterus.

Since the treatment began, each 3-6 months is a course. At the end of each course, an endometrial biopsy is performed under hysteroscopy to conduct tissue pathological examination and evaluate the treatment effect. A vaginal color Doppler ultrasound is performed every month, and a pelvic MRI is re-evaluated as needed. Additionally, a side effect assessment is performed for each course, including weight, vaginal bleeding, breast discomfort, gastrointestinal symptoms, liver and kidney function, and thrombosis.

The efficacy assessment is divided into the following categories: (1) Complete Response (CR), (2) Partial Response (PR), (3) Disease Unresponsive or Stable Disease (NC/SD), (4) Disease Progression (PD), and (5) Relapse.

The main measurement indicator is the time required for the first complete remission. The secondary measurement indicators are the one-year complete remission rate, the two-year disease recurrence rate, the cumulative pregnancy rate, pregnancy duration, pregnancy outcomes, changes in serum indicators, and pathological markers.

Inclusion Criteria:

• Endometrioid adenocarcinoma G2, diagnosis by pathological.
• The lesion is limited to the endometrium.
• FIGO (2009) staging is IA.
• Age less than 45.
• Strongly request to preserve fertility.
• Sign informed consent.

Exclusion Criteria:

• The tumor has invaded the muscle layer.
• FIGO (2009) stage IB or higher.
• Endometrioid adenocarcinoma G1, G3, or non-endometrioid cancer
• There are malignant tumors in other systems.
• Have contraindications for conservative treatment or drug use.
• Have been judged by the researcher to be unsuitable for childbearing.

Female only